The present invention relates generally to microfluidic devices and to methods for executing and controlling microfluidic processes.
Within a living cell, there are several thousand substances required to assure a proper biological functionality. These substances include, for example, proteins, lipids, carbohydrates, nucleic acids, and small molecule metabolites. A number of techniques have been developed for analyzing these biological substance classes, such as two-dimensional gel electrophoresis or liquid chromatography followed by mass spectrometry. Besides this, science is still aiming for apparatuses and instruments helping to improve the performance of synthesis and analysis with respect to an efficient time/money to product ratio.
For this purpose, it is well known in the art to integrate microfluidic processes on chips. Such chips comprise commonly a sample inlet and a functional/detection area. Highly integrated processes can be executed, for example, with multilayer plastic chips comprising a structure, as disclosed for example in the U.S. Pat. No. 5,500,071 or U.S. Pat. No. 6,613,560.
Microfluidic devices can be used for example for the electrophoretic and analysis of DNA, RNA, and proteins or for executing a chromatographic process, for example a reversed phase column separation, followed by mass spectrometry. Another possibility to analyze samples known in the field is to provide microfluidic devices with an optical detection area. They normally comprise a microfluidic structure and can be adapted for executing an electrophoresis analysis process. Chips fitted out with an optical detection area commonly comprise transmissible material, in particular glass layers, with an inserted fluid conducting structure. Microfluidic chips comprising glass are disclosed for example in the U.S. Pat. No. 6,495,104 B1.